Evaluation of Plastic Waste Management in Thailand Using Material ...

2.3.3.2 Re-melted to make products
PET bottles from sorted household wastes are collected, compressed and packed by
municipalities for transportation to plants operated by recycling businesses. At the
recycling plant, the waste is sorted to remove impurities, and the remaining PET bottles
then shredded and cleaned, foreign bodies are non-resins are removed and the remainder
turned into flakes and pellets for recycling. The recycled materials are then sent to textile
and sheet-making plants, where they are again melted down to make into textile and sheet
products (Plastic Waste Management Institute, 2009).
2.3.3.3 Monomerization: PET bottles to PET bottles
The method chemically decomposes the used PET bottles into their component monomers
(de-polymerization), and they are made into new PET bottles from this stage.
2.3.4 Case study of plastic waste recycling
2.3.4.1 Waste recycling in Thailand
Wongpanit Company is an example of success in recycling activities with the cooperation
of informal sector and public participation. The company buys at least 100 different kinds
of wastes, mainly plastic, paper, metal, and glass bottles. About 20 percent of recycled
materials are exported to China, the rest sold on domestic market. The company earns 200
million Baht in 1999. The business does not only increase the revenue of people, who
participate in recycling activities, it has, at the same time, halved the daily volume of waste
collected (Kittikanya, 2001).
The most plastic collected by the Wongpanit Company are Polypropylene (PP),
Polystyrene (PS), Polyethylene (PE), and Polyvinylchloride (PVC). After collection, the
company always sorts plastic wastes into each of these four groups. In each group, plastic
wastes are also sorted into different colors such as clear, green, red, white, blue, and black.
Contaminants (e.g. aluminum, foils, etc.) must be removed. The plastic is then crushed,
washed, dried, packed and sent to a plastic recycling plant in Samut Prakarn province.
Some types of plastic are not recycled in Thailand, e.g. PVC because the quality of
recycled PVC is lower than the virgin materials. PVC plastic scraps are exported to
Myanmar, where there is a market for the lower quality products. Polyethylene plastic
(PET) from cooking oil and some water bottles are packed with a hydraulic compactor and
exported to China for making elastic fibers and textile fibers (Foppes, 2000).
2.3.4.2 Waste recycling in Hong Kong
About 1.6 million tons of plastic wastes were recovered in Hong Kong. The amount
recovered in 2010 increased by 366 thousand tons (or 30%) as compared with 2009. The
recovered plastic waste was mostly exported to the Mainland and Vietnam for recycling
(99.8% or 1.5 million tons).
Most local plastic recyclers consume only clean plastic wastes. The plastic waste recycling
process starts with the sorting by resin types. The plastics are rinsed to remove
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